Jamie H. Warner

Department of Materials, University of Oxford, UK

Defects and dopants in 2D materials influence their properties and understanding their structure at the atomic level is crucial. I will show how aberration corrected transmission electron microscopy is used to probe graphene and MoS2 monolayers at the atomic level. This will include vacancy defects, substitutional dopants and surface adatoms. Combining scanning transmission electron microscopy with electron energy loss spectroscopy enables single atom measurements of bonding states and elemental identification. Using an in-situ heating holder, I will show how the migration of vacancies leads to new defect structures not seen at room temperature. Edge terminations are also shown, presenting low energy reconstructions that help minimize strain and unsaturated bonds.